liesen/ruff-lsp

A Language Server Protocol implementation for Ruff.

ruff-lsp

A Language Server Protocol implementation for Ruff, an extremely fast Python linter and code transformation tool, written in Rust.

Enables Ruff to be used in any editor that supports the LSP, including Neovim, Sublime Text, Emacs and more.

For Visual Studio Code, check out the Ruff VS Code extension.

Highlights

"Quick Fix" actions for auto-fixable violations (like unused imports)

"Fix all": automatically fix all auto-fixable violations

"Organize Imports": isort-compatible import sorting

Installation and Usage

ruff-lsp is available as ruff-lsp on PyPI:

pip install ruff-lsp

From there, ruff-lsp can be used with any editor that supports the Language Server Protocol, including Neovim, Emacs, Sublime Text, and more.

Example: Neovim

For example, to use ruff-lsp with Neovim, install ruff-lsp from PyPI along with nvim-lspconfig. Then, add something like the following to your init.lua:

-- See: https://github.com/neovim/nvim-lspconfig/tree/54eb2a070a4f389b1be0f98070f81d23e2b1a715#suggested-configuration
local opts = { noremap=true, silent=true }
vim.keymap.set('n', '<space>e', vim.diagnostic.open_float, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist, opts)

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
  -- Enable completion triggered by <c-x><c-o>
  vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  -- See `:help vim.lsp.*` for documentation on any of the below functions
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
  vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
  vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
  vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
  vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, bufopts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
  vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, bufopts)
  vim.keymap.set('n', '<space>ca', vim.lsp.buf.code_action, bufopts)
  vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
  vim.keymap.set('n', '<space>f', function() vim.lsp.buf.format { async = true } end, bufopts)
end

-- Configure `ruff-lsp`.
-- See: https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#ruff_lsp
-- For the default config, along with instructions on how to customize the settings
require('lspconfig').ruff_lsp.setup {
  on_attach = on_attach,
  init_options = {
    settings = {
      -- Any extra CLI arguments for `ruff` go here.
      args = {},
    }
  }
}

Upon successful installation, you should see Ruff's diagnostics surfaced directly in your editor:

Note that if you're using Ruff alongside another LSP (like Pyright), you may want to defer to that LSP for certain capabilities, like textDocument/hover:

local on_attach = function(client, bufnr)
  -- Disable hover in favor of Pyright
  client.server_capabilities.hoverProvider = false
end

require('lspconfig').ruff_lsp.setup {
  on_attach = on_attach,
}

Ruff also integrates with coc.nvim:

"languageserver": {
  "ruff-lsp": {
    "command": "ruff-lsp",
    "filetypes": ["python"]
  }
}

Example: Sublime Text

To use ruff-lsp with Sublime Text, install Sublime Text's LSP and LSP-ruff package.

Upon successful installation, you should see errors surfaced directly in your editor:

Example: Helix

To use ruff-lsp with Helix, add something like the following to ~/.config/helix/languages.toml:

[[language]]
name = "python"
scope = "source.python"
language-server = { command = "ruff-lsp" }
config = { settings = { args = [] } }

Upon successful installation, you should see errors surfaced directly in your editor:

Example: Lapce

To use ruff-lsp with Lapce, install the lapce-ruff-lsp plugin (which wraps ruff-lsp) from the Lapce plugins panel.

Upon successful installation, you should see errors surfaced directly in your editor:

Example: Kate

To use ruff-lsp with Kate, add something like the following to the LSP client's settings.json:

{
  "servers": {
    "python": {
      "command": ["ruff-lsp"],
      "url": "https://github.com/astral-sh/ruff-lsp",
      "highlightingModeRegex": "^Python$"
    }
  }
}

Settings

The exact mechanism by which settings will be passed to ruff-lsp will vary by editor. However, the following settings are supported:

Settings	Default	Description
args	[]	Additional command-line arguments to pass to ruff, e.g., "args": ["--config=/path/to/pyproject.toml"]. Supports a subset of Ruff's command-line arguments, ignoring those that are required to operate the LSP, like --force-exclude and --verbose.
logLevel	error	Sets the tracing level for the extension: error, warn, info, or debug.
path	[]	Path to a custom ruff executable, e.g., ["/path/to/ruff"].
interpreter	[]	Path to a Python interpreter to use to run the linter server.
run	onType	Run Ruff on every keystroke (onType) or on save (onSave).
organizeImports	true	Whether to register Ruff as capable of handling source.organizeImports actions.
fixAll	true	Whether to register Ruff as capable of handling source.fixAll actions.
codeAction.fixViolation.enable	true	Whether to display Quick Fix actions to autofix violations.
codeAction.disableRuleComment.enable	true	Whether to display Quick Fix actions to disable rules via noqa suppression comments.

Development

• Install just, or see the justfile for corresponding commands.
• Create and activate a virtual environment (e.g., python -m venv .venv && source .venv/bin/activate).
• Install development dependencies (just install). To run the test_format.py test, you need to install a custom ruff build with --features format, e.g. maturin develop --features format -m ../ruff/crates/ruff_cli/Cargo.toml.
• To automatically format the codebase, run: just fmt.
• To run lint and type checks, run: just check.
• To run tests, run: just test. This is just a wrapper around pytest, which you can use as usual.

License

MIT